Leo IV of Byzantium

Leo IV "the Khazar" of Byzantium (25 January 750-8 September 780) was the emperor of the Byzantine Empire from 775 to 780, succeeding Constantine V of Byzantium and preceding Constantine VI of Byzantium.

Biography
Leo was born on 25 January 750 to the House of Isauros. He married Irene, a noblewoman of the Byzantine Empire from Athens, and he succeeded his father Emperor Constantine V of Byzantium as emperor upon his death in 775. Leo allowed monks to return to monasteries, although his father persecuted them due to his iconoclasm. Leo had a son, the future Constantine VI of Byzantium, but in 780 he died of fever while on campaign against the First Bulgarian Empire.